/* GDB routines for manipulating the minimal symbol tables.
- Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
- 2002, 2003, 2004
- Free Software Foundation, Inc.
+ Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
+ 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
Contributed by Cygnus Support, using pieces from other GDB modules.
This file is part of GDB.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
/* This file contains support routines for creating, manipulating, and
Note: One instance where there may be duplicate minimal symbols with
the same name is when the symbol tables for a shared library and the
symbol tables for an executable contain global symbols with the same
- names (the dynamic linker deals with the duplication). */
+ names (the dynamic linker deals with the duplication).
+
+ It's also possible to have minimal symbols with different mangled
+ names, but identical demangled names. For example, the GNU C++ v3
+ ABI requires the generation of two (or perhaps three) copies of
+ constructor functions --- "in-charge", "not-in-charge", and
+ "allocate" copies; destructors may be duplicated as well.
+ Obviously, there must be distinct mangled names for each of these,
+ but the demangled names are all the same: S::S or S::~S. */
struct minimal_symbol *
lookup_minimal_symbol (const char *name, const char *sfile,
return NULL;
}
-
/* Search through the minimal symbol table for each objfile and find
the symbol whose address is the largest address that is still less
- than or equal to PC, and matches SECTION (if non-null). Returns a
+ than or equal to PC, and matches SECTION (if non-NULL). Returns a
pointer to the minimal symbol if such a symbol is found, or NULL if
PC is not in a suitable range. Note that we need to look through
ALL the minimal symbol tables before deciding on the symbol that
struct minimal_symbol *best_symbol = NULL;
struct obj_section *pc_section;
- /* pc has to be in a known section. This ensures that anything beyond
- the end of the last segment doesn't appear to be part of the last
- function in the last segment. */
+ /* PC has to be in a known section. This ensures that anything
+ beyond the end of the last segment doesn't appear to be part of
+ the last function in the last segment. */
pc_section = find_pc_section (pc);
if (pc_section == NULL)
return NULL;
- /* If no section was specified, then just make sure that the PC is in
- the same section as the minimal symbol we find. */
- if (section == NULL)
- section = pc_section->the_bfd_section;
+ /* We can not require the symbol found to be in pc_section, because
+ e.g. IRIX 6.5 mdebug relies on this code returning an absolute
+ symbol - but find_pc_section won't return an absolute section and
+ hence the code below would skip over absolute symbols. We can
+ still take advantage of the call to find_pc_section, though - the
+ object file still must match. In case we have separate debug
+ files, search both the file and its separate debug file. There's
+ no telling which one will have the minimal symbols. */
- /* FIXME drow/2003-07-19: Should we also check that PC is in SECTION
- if we were passed a non-NULL SECTION argument? */
+ objfile = pc_section->objfile;
+ if (objfile->separate_debug_objfile)
+ objfile = objfile->separate_debug_objfile;
- for (objfile = object_files;
- objfile != NULL;
- objfile = objfile->next)
+ for (; objfile != NULL; objfile = objfile->separate_debug_objfile_backlink)
{
/* If this objfile has a minimal symbol table, go search it using
a binary search. Note that a minimal symbol table always consists
if (objfile->minimal_symbol_count > 0)
{
+ int best_zero_sized = -1;
+
msymbol = objfile->msymbols;
lo = 0;
hi = objfile->minimal_symbol_count - 1;
== SYMBOL_VALUE_ADDRESS (&msymbol[hi + 1])))
hi++;
+ /* Skip various undesirable symbols. */
+ while (hi >= 0)
+ {
+ /* Skip any absolute symbols. This is apparently
+ what adb and dbx do, and is needed for the CM-5.
+ There are two known possible problems: (1) on
+ ELF, apparently end, edata, etc. are absolute.
+ Not sure ignoring them here is a big deal, but if
+ we want to use them, the fix would go in
+ elfread.c. (2) I think shared library entry
+ points on the NeXT are absolute. If we want
+ special handling for this it probably should be
+ triggered by a special mst_abs_or_lib or some
+ such. */
+
+ if (msymbol[hi].type == mst_abs)
+ {
+ hi--;
+ continue;
+ }
+
+ /* If SECTION was specified, skip any symbol from
+ wrong section. */
+ if (section
+ /* Some types of debug info, such as COFF,
+ don't fill the bfd_section member, so don't
+ throw away symbols on those platforms. */
+ && SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
+ && (!matching_bfd_sections
+ (SYMBOL_BFD_SECTION (&msymbol[hi]), section)))
+ {
+ hi--;
+ continue;
+ }
+
+ /* If the minimal symbol has a zero size, save it
+ but keep scanning backwards looking for one with
+ a non-zero size. A zero size may mean that the
+ symbol isn't an object or function (e.g. a
+ label), or it may just mean that the size was not
+ specified. */
+ if (MSYMBOL_SIZE (&msymbol[hi]) == 0
+ && best_zero_sized == -1)
+ {
+ best_zero_sized = hi;
+ hi--;
+ continue;
+ }
+
+ /* If we are past the end of the current symbol, try
+ the previous symbol if it has a larger overlapping
+ size. This happens on i686-pc-linux-gnu with glibc;
+ the nocancel variants of system calls are inside
+ the cancellable variants, but both have sizes. */
+ if (hi > 0
+ && MSYMBOL_SIZE (&msymbol[hi]) != 0
+ && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
+ + MSYMBOL_SIZE (&msymbol[hi]))
+ && pc < (SYMBOL_VALUE_ADDRESS (&msymbol[hi - 1])
+ + MSYMBOL_SIZE (&msymbol[hi - 1])))
+ {
+ hi--;
+ continue;
+ }
+
+ /* Otherwise, this symbol must be as good as we're going
+ to get. */
+ break;
+ }
+
+ /* If HI has a zero size, and best_zero_sized is set,
+ then we had two or more zero-sized symbols; prefer
+ the first one we found (which may have a higher
+ address). Also, if we ran off the end, be sure
+ to back up. */
+ if (best_zero_sized != -1
+ && (hi < 0 || MSYMBOL_SIZE (&msymbol[hi]) == 0))
+ hi = best_zero_sized;
+
+ /* If the minimal symbol has a non-zero size, and this
+ PC appears to be outside the symbol's contents, then
+ refuse to use this symbol. If we found a zero-sized
+ symbol with an address greater than this symbol's,
+ use that instead. We assume that if symbols have
+ specified sizes, they do not overlap. */
+
+ if (hi >= 0
+ && MSYMBOL_SIZE (&msymbol[hi]) != 0
+ && pc >= (SYMBOL_VALUE_ADDRESS (&msymbol[hi])
+ + MSYMBOL_SIZE (&msymbol[hi])))
+ {
+ if (best_zero_sized != -1)
+ hi = best_zero_sized;
+ else
+ /* Go on to the next object file. */
+ continue;
+ }
+
/* The minimal symbol indexed by hi now is the best one in this
objfile's minimal symbol table. See if it is the best one
overall. */
- /* Skip any absolute symbols. This is apparently what adb
- and dbx do, and is needed for the CM-5. There are two
- known possible problems: (1) on ELF, apparently end, edata,
- etc. are absolute. Not sure ignoring them here is a big
- deal, but if we want to use them, the fix would go in
- elfread.c. (2) I think shared library entry points on the
- NeXT are absolute. If we want special handling for this
- it probably should be triggered by a special
- mst_abs_or_lib or some such. */
- while (hi >= 0
- && msymbol[hi].type == mst_abs)
- --hi;
-
- /* If "section" specified, skip any symbol from wrong section */
- /* This is the new code that distinguishes it from the old function */
- if (section)
- while (hi >= 0
- /* Some types of debug info, such as COFF,
- don't fill the bfd_section member, so don't
- throw away symbols on those platforms. */
- && SYMBOL_BFD_SECTION (&msymbol[hi]) != NULL
- && SYMBOL_BFD_SECTION (&msymbol[hi]) != section)
- --hi;
-
if (hi >= 0
&& ((best_symbol == NULL) ||
(SYMBOL_VALUE_ADDRESS (best_symbol) <
struct minimal_symbol *
lookup_minimal_symbol_by_pc (CORE_ADDR pc)
{
- return lookup_minimal_symbol_by_pc_section (pc, find_pc_mapped_section (pc));
+ /* NOTE: cagney/2004-01-27: This was using find_pc_mapped_section to
+ force the section but that (well unless you're doing overlay
+ debugging) always returns NULL making the call somewhat useless. */
+ struct obj_section *section = find_pc_section (pc);
+ if (section == NULL)
+ return NULL;
+ return lookup_minimal_symbol_by_pc_section (pc, section->the_bfd_section);
}
\f
struct msym_bunch *new;
struct minimal_symbol *msymbol;
- if (ms_type == mst_file_text)
- {
- /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
- the minimal symbols, because if there is also another symbol
- at the same address (e.g. the first function of the file),
- lookup_minimal_symbol_by_pc would have no way of getting the
- right one. */
- if (name[0] == 'g'
- && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
- || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
- return (NULL);
+ /* Don't put gcc_compiled, __gnu_compiled_cplus, and friends into
+ the minimal symbols, because if there is also another symbol
+ at the same address (e.g. the first function of the file),
+ lookup_minimal_symbol_by_pc would have no way of getting the
+ right one. */
+ if (ms_type == mst_file_text && name[0] == 'g'
+ && (strcmp (name, GCC_COMPILED_FLAG_SYMBOL) == 0
+ || strcmp (name, GCC2_COMPILED_FLAG_SYMBOL) == 0))
+ return (NULL);
- {
- const char *tempstring = name;
- if (tempstring[0] == get_symbol_leading_char (objfile->obfd))
- ++tempstring;
- if (strncmp (tempstring, "__gnu_compiled", 14) == 0)
- return (NULL);
- }
- }
+ /* It's safe to strip the leading char here once, since the name
+ is also stored stripped in the minimal symbol table. */
+ if (name[0] == get_symbol_leading_char (objfile->obfd))
+ ++name;
+
+ if (ms_type == mst_file_text && strncmp (name, "__gnu_compiled", 14) == 0)
+ return (NULL);
if (msym_bunch_index == BUNCH_SIZE)
{
add_minsym_to_hash_table (msym, objfile->msymbol_hash);
msym->demangled_hash_next = 0;
- if (SYMBOL_DEMANGLED_NAME (msym) != NULL)
+ if (SYMBOL_SEARCH_NAME (msym) != SYMBOL_LINKAGE_NAME (msym))
add_minsym_to_demangled_hash_table (msym,
objfile->msymbol_demangled_hash);
}
struct msym_bunch *bunch;
struct minimal_symbol *msymbols;
int alloc_count;
- char leading_char;
if (msym_count > 0)
{
each bunch is full. */
mcount = objfile->minimal_symbol_count;
- leading_char = get_symbol_leading_char (objfile->obfd);
for (bunch = msym_bunch; bunch != NULL; bunch = bunch->next)
{
for (bindex = 0; bindex < msym_bunch_index; bindex++, mcount++)
- {
- msymbols[mcount] = bunch->contents[bindex];
- if (SYMBOL_LINKAGE_NAME (&msymbols[mcount])[0] == leading_char)
- {
- SYMBOL_LINKAGE_NAME (&msymbols[mcount])++;
- }
- }
+ msymbols[mcount] = bunch->contents[bindex];
msym_bunch_index = BUNCH_SIZE;
}
a duplicate function in case this matters someday. */
CORE_ADDR
-find_solib_trampoline_target (CORE_ADDR pc)
+find_solib_trampoline_target (struct frame_info *frame, CORE_ADDR pc)
{
struct objfile *objfile;
struct minimal_symbol *msymbol;
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